Question

Nodular cast iron is also called as:
1. Graphite iron
2. Malleable cast iron
3. Grey cast iron
4. White cast iron

Answer 1

Correct Answer - Option 1 : Graphite iron

Explanation:

• It is also known as “spheroidal graphite iron” or “ductile iron” or “high strength cast iron”.
• It is achieved by adding a small amount of magnesium or cerium to the pure molten grey iron that has been subjected to desulphurization.
• The presence of cerium and magnesium causes the graphite to precipitate during solidification of molten alloy in the form of small spheroids. These spheroids result in less concentration effect as compared to the flakes in the grey iron resulting in high ductility, strength, toughness, and stiffness of a material.
• Ductile cast iron is used for making machine parts like axles, brackets, levers, crankshaft housing, die pads, and die shoes.